extruder insert for flexable filament

thingiverse

I got this all-metal extrusion set for 3 Euros, available at www.aliexpress.com/item/Free-Shipping-MK8-extruder-aluminum-block-DIY-kit-Makerbot-dedicated-single-nozzle-extrusion-head-aluminum-block/32436314438.html. A nice thing about it is that you can regulate the force applied to the filament. However, this kit will ruin flexible filament as it wraps around the gear. To fix this problem, I created an insert guiding the filament from the extruder gears to the pneumatic coupling. You'll need a Nema 17 stepper motor and pneumatic couplings with M6 thread. You can use the ones used by the stock extruder. Additionally, you'll require two M3 bolts, 20mm long. The insert typically doesn't want to be screwed in straight, so I first screw in the pneumatic coupler at the spot where the insert will go. Then I take a 2mm drill bit and insert it into the coupler, with most of the drill bit sticking out on the other side of the "golden" extruder bar. Next, I put the printed insert over the drill so that it has no choice but to enter the thread straight. This clears any debris from printing and allows the insert to go in the thread easily. After that, I unscrew everything and screw the insert into place. There are two ways to orientate the insert: the part with the biggest "bite" out of it should face the ball bearing. Tips for printing with flexible filaments include printing really slow, at 30-40mm/second or even 10-20mm/s, or as low as 5mm/s. Playing with retraction settings can also help - if you have a lot of stringiness, reduce the amount of retraction, and if you get filament blobs, increase retraction speed or distance. Using Capricorn XS (the darker blue) tubing in my bowden setup has helped me print flexible filaments because it has a slightly smaller inner diameter. This restricts the path of the filament so it has less room to squiggle and become even more spring-like. Additionally, Capricorn XS reduces friction. As shipping costs are high, I advise ordering 2 meters of tubing and asking for a sample of the TL tube. When I ordered, there was a 10% discount code in the Capricorn Facebook group. I learned the hard way that it's prudent to have spare parts: a complete hotend, several nozzles, two types of pneumatic couplings (PC4-M6 and PC4-M10), PTFE tubing, extruder gear (preferably one that matches half the profile of the filament), fans. I prefer Sunon maglift fans on aliexpress over the overpriced Noctua fans. To secure the PTFE tubing to the pneumatic coupling, use a small tie wrap or a retaining clip. This can be found at https://www.thingiverse.com/thing:2798864